<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <link href="bootstrap.min.css" rel="stylesheet">
    <title></title>
</head>
<body>
    <div class="container">
        <div class="dropdown pull-right">
            <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu" data-toggle="dropdown" aria-expanded="true">
                地铁线路
                <span class="caret"></span>
            </button>
            <ul class="dropdown-menu dropdown-menu-right" role="menu" aria-labelledby="dropdownMenu">
                <!--声明标题-->
                <li role="presentation" class="dropdown-header">地铁</li>
                <li role="presentation"><a role="menuitem" tabindex="-1" href="#" >1号线</a></li>
                <!--禁用选项-->
                <li role="presentation" class="disabled"><a role="menuitem" tabindex="-1" href="#">2号线</a></li>
                <li role="presentation"><a role="menuitem" tabindex="-1" href="#">3号线</a></li>
                <!--分割线-->
                <li role="presentation" class="divider"></li>
                <li role="presentation"><a role="menuitem" tabindex="-1" href="#">4号线</a></li>
            </ul>
        </div>

    </div>

</body>
<script src="jquery-2.1.3.js"></script>
<script src="bootstrap.min.js"></script>
</html>